Sarah Barrass, aged 34, of Gregg House Road, Shiregreen, is due to appear at Sheffield Crown Court charged with murder alongside 37-year-old Brandon Machin, of no fixed abode.
The pair are accused of killing 14-year-old Blake Barrass and Tristan Barrass, 13, last Friday.
Barrass is also accused of three counts of attempted murder against two other children.
Those children – as well as two other youngsters – cannot be named for legal reasons.
A High Court injunction banning their identification covers social media comments, photographs or anything else that could lead to their identification.
South Yorkshire Police has warned that those who name the youngsters could be charged with contempt of court.
Barrass and Machin were charged after emergency services were called to a property in Shiregreen on Friday, May 24.
Six children were taken to hospital, including Blake and Tristan, who later died.
The other four children were released from hospital on Saturday.
Results of post mortem examinations to establish exactly how Blake and Tristan died have not yet been made public.
Barrass and Machin appeared at Sheffield Magistrates’ Court yesterday and were remanded in custody ahead of a Crown Court hearing today.
More to follow.